1. Field of the Invention
This invention relates generally to automotive rack and pinion power steering gears and, more particularly, to outer housings for such gears.
2. Description of the Prior Art
U.S. Pat. No. 4,454,801, issued June 19, 1984 to Chris R. Spann and assigned to the assignee of this invention, describes a rotary valve rack and pinion power steering gear having a single or one-piece die cast aluminum outer housing which supports the pinion shaft and the rotary valve. One piece die cast outer housings are attractive for minimizing weight and maximizing manufacturing efficiency. However, for maximizing resistance to abrasion by internal moving parts, such as elements of the rotary valve, and for minimizing potential wall porosity around the rotary valve, the portion of the housing around the rotary valve is desirably fabricated from a more dense and abrasion resistant material such as ferrous metal. To that end, rotary valve rack and pinion power steering gears have been proposed which include separate, bolted-together pinion and valve housings. A composite housing and method of assembling the same according to this invention represents an improvement over such bolted-together housings.